Signaling system



C. WISSPEINTNER ET AL SIGNALING SYSTEM Filed Sept. 24, 1950 FIG. Z

CHRISTIAN WISSPEINTNER GEORG CHODZIESNER ATTORNEY Patented Oct. 18, 1932UNITED STATES PATENT OFFICE CHRISTIAN WISSPEINTNER, 0FBERLIN-CHARLQT'QENBURG, AND GEOBG GHODZIESNER,

OF BERLIN-ZEHLENDORF, GERMANY, ASSIGNORS T0 INTERNATIONAL, COMMUNI-CATIONS LABORATORIES, INCORPORATED, OF NEW YORK, N. Y;

SIGNALING SYSTEM Application filed September 24, 1930, Serial No.484,045, and in Germany September 26, 1929.

The present invention relates to a circuit arrangement for signalingpurposes, in particular for telegraphic transmission of intelligenceaccording to the closed circuit principle.

Arrangements are known in which the receiving magnet of a subscriberstation is operated by short circuit when receiving a communication. Afaultless working is not given by this arrangement. According to thepresent'invention the disadvantages of the short circuit are avoided inthis way, that when receiving a communication the receiving magnet isoperated in this way that a resistance is put parallel to it.

A further. advantage of the invention consists in this, that instead oftwo batteries or a battery with centre tapping as used in the knowncircuits, only one battery without centre tapping is used.

In the accompanying drawing Figs. 1 and 2 show embodiments of theinventive idea. In the Fig. l are shown the receiving magnet EM and'thesending contact SK of a telegraph station. In the exchange are locatedthe receiving relay ER and the transmitting relay SR. If the subscriberstation is at rest the following'closed' circuit current will flow inthe receiving magnet EM: battery, winding II of the relay SR, receivingmagnet EM, sending contact SK, contact 70 of the receiving relay ER,back to the battery. Through the winding I of the transmitting relay SRcurrent flows over battery, winding I of relay SR, resistance R contact70 of the receiving relay ER, back to battery. The transmitting relay isa polarized relay which is set neutral. The contact 81 of thetransmitting relay is shown in its idle position.

The switching operations are described with the aid of Fig. 1 which comeinto cf fect'when transmitting a communication by opening'and closingthe sending contact SK. By opening the sending contact SK the abovedescribed closed circuit is interrupted. In this way the receivingmagnet EM which is inserted in the closed circuit is released, wherebythe recording operation is efiected in the known manner.: Besides thisthe winding II of the sending relay SR becomes currentless through theopening of the sending contact SK, whereby the contact 81 is reversed.These switching operations are re peated according to the opening andclosing of the sending contact SK. By opening and closing the contacts81" the impulses are transmitted to the junction, in this way, that aclifi'erent potential is put to the junction alternately.

At the reception of a communication the following switching operationstake place:-

Owing to the alternate responding and dropping of the receiving relay ERthe contact is is correspondingly reversed. The above described closedcircuit isinterrupted for the receiving magnet EM by reversing thecontact is. In order to attain a faultless and positive working of thereceiving magnet EM according to the invention, the highohmic resistanceR parallel to the receiving I magnet EM is put in series with thesending relay SR each time the contact 72 is reversed. The sending relaySR cannot operate its contact 81 when receiving a communication, becausewhen the contact 70 is reversed a new circuit is established for thewinding II of sending relay SR as follows: battery, winding II ofsending relay SR, resistance R contact K, back to battery. The sendingrelay SR consequently remains operated. The size of the resistance R isequal to the size of the resistance R and each of these resistances istwice as large as the resistance of the apparatus and the line. Theresistance R is notdesigned as a pure ohmic resistance but is at thesame time used as a balancing device for the line. The currentconditions in the sending relay SR are not altered during the transittimes at the receiving relay ER owing to the condensers.

A further embodiment of the inventive idea is explained with the aid ofthe Fig. 2. If the arrangement is at rest then the following closedcircuit current flows: battery,

resting contact of receiving relay ER winda ing of receiving magnet EMsending contact SK winding I of the relay SR back to the battery. Thefollowing circuit exists for the winding II of relay SR battery, restingcontact [70 of receiving relay ER cal resistance R winding II of therelay SR back to battery. The relay SR is designed as a neutrally set,polarized relay. During transmission the above described closed circuitis interrupted by the opening of the sending contact SK The transmittingrelay SR is thereby released according to the opening of the sendingcontact SK and by reversion of the contact 87 the impulses produced bythe sending contact SK are transmitted over the junction in thatdifferent potential is alternately put to same. By the opening of thesending contact 8K the receiving magnet EM is also released where by therecording operation is effected in the known manner. p I c A \Vhenreceiving a communication the switching processes according to thearrangement in Fig. 2 are as follows:

By reversing the contact the receiving magnet EN 1 is released wherebyaccording to the invention the resistance R parallel to the receivingmagnet EM is connected in series with the transmitting relay SR in orderto obtain a faultless and positive operation of the receiving magnet EMOwing to the reversion of the contact is the sending relay'SR cannotoperate its contact sr because when the contact 70 is reversed thefollowing circuits for the sending relay SR are established. The circuitfor the winding II of the relay SR is as follows: battery, reversedcontact 70 of receiving relay ER resistance Rfiwinding II of the sendingrelay SR back to battery. The circuit for the winding I of the relay SRflows as follows: battery, reversed contact 70 of receiving relay ERresistance R winding I of the send ing relay SR back to battery. Thesize of the resistance R is equal to .the size of the resistance. R andeach resistance is half as large as the resistance R the half size ofwhich is equal to the resistance of the apparatus plus the line.

For this reason the relay SR cannot reverse its sending contact sriduring the reception of a signal.

Instead of two batteries or one battery with centre tapping there isonly one battery according to the invention which is connected directlyto the centre of the sending relay SR or SR hat is claimed is:

1. In a telegraph system, the combination including a normally closedloop circuit ex tending between two stations, an electromagneticreceiving device and a transmitting key at one station connected in theloop, a sending relay at the other station having a wind ing connectedin the loop and controlled by the transmitting key, a source of currentat the other of said stations connected in the loop, a receiving relayat the said other station having its marking contact in the loop, asecond winding for the sending relay included in a normally closedcircuit containing said source of current and said marking contact, andmeans including said source of current for maintaining the sending relayin its normal position upon closure of the spacingcontact of thereceiving relay to operate the receiving device.

2. In a telegraph system, the combination including a telegraph receiverat a local station, a differentially wound polar sending relay and areceiving relay at a repeating station, a line circuit connecting thestations and having the receiver and a winding of the sending relayconnected therein, a local circuit including another winding ofthesending relay, a source of current at the'repeating station normallyconnected in both circuits through the marking contact of the receivingrelay, a transmitting key at the local station for controlling theoperation of the sending relay, and means including said source ofcurrent for holding the sending relay in its normal position uponclosure of the spacing contact of the receiving relay to operate thereceiver.

3. In a telegraph system, the combination including a. telegraphreceiver at a local station, a differentially wound polar sending relayand a receiving relay at a repeating station, a line circuit connectingthe stations and having the receiver and a winding of the sending relayconnected therein, a local circuit including another winding of thesending relay, a source of current at the repeating station normallyconnected in both circuits through the marking contact of the receivingrelay, a transmitting key at the local station for controlling theoperation of the sending relay, a resistance in the local circuit, asecond resistance, and a local circuit including the second resistanceand the line circuit winding of the sending relay established by closureof the spacing contact which simultaneously includes the other windingof the sending relay and the first mentioned resistance in the linecircuit.

4. In a telegraph system, the combination includin a telegraph receiverat a local station, sending and receiving relays at a repeating station,a line circuit connecting the stations and having a winding of thesending relay and the receiver connected in series therein, a localcircuit including another winding of the sending relay, a source ofcurrent at the repeating station and the receiving relay marking contactbeing common to said circuits, a transmitting key at the local stationfor controlling the operation of the sending I relay, and meansincluding said source of current for maintaining the sending relay inits normal position upon closure of the spacing contact of the receivingrelay to operate the receiver.

5. In a telegraph system, the combination including a telegraph receiverat a local station, a polar sending relay having two windings, areceiving relay, both relays being located at a repeating station, aline circuit connecting the stations and having the receiver and onewinding of the sending relay connected therein, a normally closed localcircuit including the other winding of the sending relay, both the linecircuit and the local circuit being closed while the marking contact ofthe receiving relay is closed, a transmitting key at the local stationcontrolling the operation of the sending relay, and means including asingle source of current at the repeating station co-operating with thesending relay upon the operation of the transmitting key and effectiveto hold the sending relay in its normal position upon closure of thespacing contact of the receiving relay to operate the receiver.

6. In a telegraph system, the combination according to claim 1 togetherwith means to operate the spacing contact of the receiving relay, aholding circuit for the sending relay, and means wherein the closure ofsaid spacing contact closes the said holding circuit of the sendingrelay.

7. In a telegraph system, the combination according to claim 1 togetherwith means for operating the marking and spacing contacts of thereceiving relay, a resistance in the normally closed circuit includingthe second winding of the sending relay, and means wherein theresistance is removed therefrom by opening the said marking contact andis connected in the loop circuit by closure of the spacing contact.

8. In a telegraph system, the combination according to claim 1 togetherwith means to operate the spacing contact of the receiving relay, aholding circuit for the sending relay, and means wherein the closure ofthe spacing contact connects the said holding circuit through thewinding of the sending relay which is normally in the loop circuit.

9. In a telegraph system, the combination according to claim 1 togetherwith means to operate the spacing contact of the receiving relay, alocal circuit including a resistance, a second resistance in series withthe winding of the sending relay connected in the loop, and meanswherein the second winding of the sending relay and the resistanceincluded in the local circuit are connected in the loop upon closure ofthe spacing contact.

10. In a telegraph system, the combination according to claim 1 togetherwith means to operate the spacing contact, a local circuit, and meanswherein the closure of the spacing contact connects the second windingof the sending relay in series with the loop and the other windingconnected in the loop in said local circuit.

11. In a telegraph system, the combination according to claim 2 togetherwith means to operate the spacing contact, wherein the closure of thespacing contact interchanges the sending relay windings in therespective cir-

